/*
 * Copyright (C) 2007-2012 by XDEV Software, All Rights Reserved.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License version 3.0 as published by the Free Software Foundation.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 */

package xdev.db.jdbc;


import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

import xdev.lang.Nullable;


/**
 * The class {@link JDBCUtils} provides utility methods for JDBC related tasks.
 * 
 * @since 3.2
 * @author XDEV Software
 * 
 */
public class JDBCUtils
{
	/**
	 * Closes <code>rs</code> silently, throws no exception whether
	 * <code>rs</code> is <code>null</code> nor if an error occurs.
	 * 
	 * @param rs
	 *            {@link ResultSet} to be closed
	 */
	public static void closeSilent(final @Nullable ResultSet rs)
	{
		if(rs != null)
		{
			try
			{
				boolean closed = false;
				try
				{
					closed = rs.isClosed();
				}
				catch(AbstractMethodError e)
				{
					// old jdbc driver
				}
				
				if(!closed)
				{
					Statement statement = null;
					try
					{
						statement = rs.getStatement();
					}
					catch(SQLException e)
					{
						// swallow
					}
					if(statement != null)
					{
						statement.close();
					}
					else
					{
						rs.close();
					}
				}
			}
			catch(SQLException e)
			{
				// swallow
			}
		}
	}
}
